High Frequency High Power Converters for
Industrial Applications A Thesis by Publication submitted in
Partial Fulfilment of the Requirement for the
Degree of
Doctor of Philosophy
Pooya Davari
M.Sc, B.Eng (Electrical Engineering)
Science and Engineering Faculty
School of Electrical Engineering and Computer Science
Queensland University of Technology
Queensland, AustraliaAbstract
High power converters have found their way into many industries. Variety of industries processes have increased their requirements in power level, economy of scale, efficiency, new control method, new topologies and using new technologies (like new semiconductors). The incentive to move to higher frequencies is not only given by the reduced sizes of the passive components, magnetic core losses, but also the application demands. It is thus clear that much can be gained from moving to a design that enables operation at very high frequency. Hence in the recent years, high frequency high power converters have been one of the most active areas in research.
In this PhD research project high power converters have been considered, regarding to their power level, as two categories of high instantaneous and high average power converters. High frequency high instantaneous power converters mostly known as pulsed power supplies are studied as the main aspect of this research, and high frequency high average power converters are investigated with the specific intention on high power piezoelectric transducer applications as the second aspect.
LINKhttp://eprints.qut.edu.au/62896/1/Pooya_Davari_Thesis.pdf

India triumphed in its first interplanetary mission, placing a satellite into orbit around Mars on Wednesday morning and catapulting the country into an elite club of deep-space explorers
Scientists broke into wild cheers as the Mars Orbiter Mission, affectionately nicknamed MOM, manoeuvred into its designated place around the red planet in an operation described as "flawless".
The success marks a milestone for India's space program in demonstrating that it can conduct complex missions and act as a global launch pad for commercial, navigational and research satellites.
India was particularly proud that MOM was developed with homegrown technology and for a bargain price of about US$75 million. Nasa's much larger Mars Atmosphere and Volatile Evolution mission, or Maven, which reached its position around the red planet on Sunday, cost nearly 10 times as much at US$671 million.

Abstract
The contamination of the environment is an issue that concerns all. The toxic waste is
a major cause of contamination and a global solution to eliminate it is the use of thermal
plasma. Currently, a toxic waste inertization plant is development. This plant is basically
composed by a radio-frequency power supply (RF power supply) and an inductive plasma
torch. As the power source and the torch have a difference in impedance, it is necessary
to use a transformer. Thus, this work presents the methodology and the development
of a medium-power transformer (50 kW) operating at high frequency (400 kHz), using
software for calculating electromagnetic fields.
LINK1https://mega.co.nz/#!ywFkxD4L!eizcB0bJFhVmwXb09Ovs20qVo9ayQR-CG2PDJBeMV1A
LINK2http://docente.ifrn.edu.br/giancarlosbarbosa/dissertacao/dissertacao

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domingo, 7 de setembro de 2014

Abstract
Batteries are used on-board vehicles for broadly two applications –
starting-lighting-ignition (SLI) and vehicle traction. This thesis examines
the suitability of the rechargeable lithium battery for both these applications,
and develops algorithms for runtime prediction of the remaining battery
charge.
The largest market-share of rechargeable batteries is for the SLI
application. Lead-acid batteries rule this market presently, although a
handful of lithium SLI batteries have recently appeared on the market. The
practicality of different lithium battery chemistries has been evaluated for
this application over wide-ranging criteria and it has been found that the
batteries based on lithium iron phosphate and lithium titanate oxide
chemistries commercially available in the market are the most suitable.
Lithium SLI batteries would require a higher initial cost and additional
electronic hardware in the form of battery management and thermal
management systems, but would last the life-time of the vehicle. In fact,
with the decrease in the cost of lithium SLI batteries with higher volumes,
over the life-time of the vehicle, the total costs of the existing lead-acid
battery and the lithium battery would be about the same.
LINKhttp://www.dsea.unipi.it/Members/huriaw/phd-thesis.pdf

sábado, 6 de setembro de 2014

SUMMARY
This work was performed in the frame of collaboration between the Laboratory on Plasma
and Energy Conversion (LAPLACE), University of Toulouse, and the Second University of
Naples (SUN). This work was supported by Rongxin Power Electronic Company (China) and
concerns the use of multilevel converters in High Voltage Direct Current (HVDC)
transmission.
For more than one hundred years, the generation, the transmission, distribution and uses of
electrical energy were principally based on AC systems. HVDC systems were considered some
50 years ago for technical and economic reasons. Nowadays, it is well known that HVDC is
more convenient than AC for overhead transmission lines from 800 - 1000 km long. This
break-even distance decreases up to 50 km for underground or submarine cables.
Over the twenty-first century, HVDC transmissions will be a key point in green electric
energy development. Due to the limitation in current capability of semiconductors and
electrical cables, high power applications require high voltage converters. Thanks to the
development of high voltage semiconductor devices, it is now possible to achieve high power
converters for AC/DC conversion in the GW power range.
For several years, multilevel voltage source converters allow working at high voltage level
and draw a quasi-sinusoidal voltage waveform. Classical multilevel topologies such as NPC
and Flying Capacitor VSIs were introduced twenty years ago and are nowadays widely used
in Medium Power applications such as traction drives. In the scope of High Voltage AC/DC
converters, the Modular Multilevel Converter (MMC), proposed ten years ago by Professor R.
Marquardt from the University of Munich (Germany), appeared particularly interesting for
HVDC transmissions.
LINK http://hal.archives-ouvertes.fr/docs/00/94/53/75/PDF/SERBIA_2014.pdf

Power Loss Modeling of Individual IGBT and Advanced Voltage
Balancing Scheme for MMC in VSC-HVDC System
Gum Tae Son*, Soo Hyoung Lee** and Jung-Wook Park†Abstract – This paper presents the new power dissipation model of individual switching device in a
high-level modular multilevel converter (MMC), which can be mostly used in voltage sourced
converter (VSC) based high-voltage direct current (HVDC) system and flexible AC transmission
system (FACTS). Also, the voltage balancing method based on sorting algorithm is newly proposed to
advance the MMC functionalities by effectively adjusting switching variations of the sub-module
(SM). The proposed power dissipation model does not fully calculate the average power dissipation for
numerous switching devices in an arm module. Instead, it estimates the power dissipation of every
switching element based on the inherent operational principle of SM in MMC. In other words, the
power dissipation is computed in every single switching event by using the polynomial curve fitting
model with minimum computational efforts and high accuracy, which are required to manage the large
number of SMs. After estimating the value of power dissipation, the thermal condition of every
switching element is considered in the case of external disturbance. Then, the arm modeling for highlevel
MMC and its control scheme is implemented with the electromagnetic transient simulation
program. Finally, the case study for applying to the MMC based HVDC system is carried out to select
the appropriate insulated-gate bipolar transistor (IGBT) module in a steady-state, as well as to estimate
the proper thermal condition of every switching element in a transient state.
LINKhttp://www.jeet.or.kr/LTKPSWeb/pub/pubfpfile.aspx?ppseq=1039